JPH0756164B2 - Reinforcement structure of shrinkage joint of earthquake-resistant wall - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] The present invention relates to a reinforcing bar structure of a shrinkage joint of an earthquake resistant wall.

2. Description of the Related Art Generally, in a wall of a reinforced concrete building, concrete is liable to shrink due to drying and shrinkage, and in particular, when the outer wall is cracked, rainwater enters and causes a problem.

As a countermeasure against this crack, a joint is provided on the wall, and the crack is concentrated here to caulk the joint.
The cracks generated in the joints are concentrated in the joints as much as possible, and about half of the reinforcing bars at the joints are cut to reduce the restraint so that the cracks are not dispersed in other wall portions.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in a seismic wall, it is not possible to cut the reinforcing bar that bears the shear strength, so it is not possible to take sufficient measures against cracking due to contraction joints as described above. It was difficult to prevent water leakage.

The present invention was made in order to solve the problems in the conventional earthquake-resistant wall, and its purpose is to allow the crack width entering the joint to expand for a long period of time,
It prevents new cracks from occurring in the wall between joints and can also bear sufficient shearing force as an earthquake resistant wall during an earthquake, thereby completely preventing water leakage due to cracks, especially on the outer wall. At the same time, a high-quality reinforced concrete wall is constructed to provide a new reinforcement structure for the shrinkage joints of the earthquake-resistant wall that can reduce the maintenance cost of the building.

[Structure of the Invention] Means for Solving the Problems The reinforcing structure of the shrinkage joint portion of the earthquake-resistant wall of the first invention of the present application is appropriately arranged in a direction orthogonal to the shrinkage joint formed on the earthquake-resistant wall of the reinforced concrete building. A plurality of lateral wall muscles arranged substantially parallel to each other at intervals and being cut at both side portions of the contractive joint; and between the lateral wall muscles in parallel with the wall lateral muscles and appropriately on both side wall body portions of the contractive joint. It consists of rebars for contraction joints whose outer surface is covered with a viscoelastic layer such as epoxy resin or tar while being overlapped with the horizontal wall reinforcement, and the surface of the viscoelastic layer is in concrete. When the concrete is contact-engaged with the aggregate, the aggregate in contact with the viscoelastic layer slides and the viscoelastic layer itself creeps against long-term deformation such as drying shrinkage of concrete. Awakened and unrestrained For it to allow drying shrinkage, while short-term deformation load such as an earthquake,
It is characterized in that the viscoelastic layer and the aggregate are configured so as to effectively exert a resistance force without engaging with each other and sliding.
Moreover, the reinforcing bar structure of the contraction joint portion of the earthquake resistant wall of the second invention of the present application is arranged substantially parallel to the contraction joint formed in the earthquake resistant wall of the reinforced concrete building at an appropriate interval in a substantially parallel manner, A plurality of transverse wall muscles cut at both sides of the contraction joint; and the reinforcement joints and the side wall portions thereof are arranged so as to overlap the transverse wall muscles, and the transverse muscles and the anchoring muscles are arranged in a grid pattern. Reinforcement for shrinkage joints, which is welded and whose surface is covered with a viscoelastic layer such as epoxy resin or tar; and the concrete is dried by bringing the surface of the viscoelastic layer into contact with the aggregate in the concrete. For long-term deformation such as shrinkage, the aggregate in contact with the viscoelastic layer slides, and the viscoelastic layer itself also creeps and becomes unrestrained, enabling dry shrinkage. ,
On the other hand, it is characterized in that the viscoelastic layer and the aggregate are effectively engaged with each other against a short-term deformation load such as an earthquake without sliding due to meshing.

Example Next, an example of the present invention will be described with reference to the drawings.

In FIGS. 1 and 2, reference numeral 1 is an earthquake-resistant wall, and shrink joints 2 are formed on both side surfaces at appropriate intervals. 3 is a lateral wall of the wall, which is cut at both sides of the contraction joint 2. Numeral 4 is a contraction joint rebar, which has a required lap length 1 on both sides of the contraction joint 2 and has a required overlapping length, and is arranged so as to overlap between the lateral wall bars 3 and 3 arranged vertically. It is designed to be streaked.

As shown in the enlarged view of FIG. 3, the contraction joint reinforcing bar 4 has a thin viscoelastic layer 5 made of, for example, an epoxy resin formed on the outer surface thereof.

Therefore, even when the shrinkage of the concrete progresses, the silica sand 6 which is the aggregate in the concrete that is in contact with the surface of the viscoelastic layer 5 slides, and the viscoelastic layer 5 itself also creeps and does not exist. It is in a restrained state, and is eventually designed to allow long-term dry shrinkage of concrete.

Therefore, as shown in FIG. 4, even if the shrinkage of the concrete progresses over time, the stress of the shrink joint rebar 4 as shown by the broken line A does not occur and the deformation of the concrete is almost unrestrained. However, as shown by the solid line B, only a stress is generated by the lateral wall reinforcement 3, so that a new crack is generated at the point C where the stress reaches the crack generation stress σ ′.

When an earthquake occurs, as shown in Fig. 5,
Since the stress-strain characteristic of the contraction joint rebar 4 shown by the broken line A'has almost the same behavior as the stress-strain characteristic of the lateral wall reinforcement 3 shown by the solid line B ', a large seismic resistance performance in which the resistance forces of both are summed is exhibited.

As shown in FIG. 6, if the contraction joint reinforcing bar 4 is integrally welded to the longitudinal bar 7 at a required sliding length 1 ', the bar arranging work becomes easy.

FIG. 7 shows an embodiment of the second invention of the present application.
And fixing lines 9 are combined in a lattice shape as shown in the drawing and welded, and the outer surfaces of these are covered with a viscoelastic layer 10 of tar, urethane or the like such as an unbonded material. The thickness α of this viscoelastic layer is
α = (1/2) × L × ε (where L is the space m between contraction joints
m and ε are dry shrinkage strains of concrete). Therefore, for example, L is 3 m (3,000 mm) and ε is 5 × 1
^Assuming 0 ^-4 , α = (1/2) x 3,000 x 5 x 10 ^-4 = 0.75 mm
Becomes

As shown in FIG. 8, the contraction joint rebar 11 configured as described above is arranged with a predetermined overlap length around the contraction joint 2 of the earthquake-resistant wall 1 as a center.

As the shrinkage of concrete progresses, as shown in FIG. 9, the viscoelastic layer 10 of the anchoring bar 9 of the shrink joint rebar 11 is crushed and
Cracks are allowed under low stress conditions up to the deformation of the width of α, but if the cracks try to expand further, the anchoring streak 9 directly acts to press it down, and the lateral stirrup 8 works effectively during an earthquake, and as a seismic wall. Fully functional.

FIG. 10 shows the transverse bar 8 when the contracted joint rebar 11 behaves as described above.
It shows the relationship between the deformation and stress.

FIG. 11 shows another embodiment of the contraction joint reinforcing bar 11. The horizontal reinforcing bars 8 are arranged in an oblique lattice shape and integrally welded so that they effectively work when the shear stress of the wall is large. .

[Effects of the Invention] Epoxy resin, tar, etc. are placed on the surface of the contraction joint rebar that is arranged by overlapping with a plurality of lateral wall reinforcements cut at both sides of the earthquake-resistant contraction joint of a reinforced concrete building. By covering the viscoelastic layer and bringing the surface of the viscoelastic layer into contact engagement with the aggregate in the concrete, the viscoelastic layer is contacted against long-term deformation such as drying shrinkage of concrete. As the running aggregate slides,
The viscoelastic layer itself also creeps into an unrestrained state to allow dry shrinkage, while the short-term deformation load such as an earthquake causes the viscoelastic layer and the aggregate to mesh and slide. Since it is configured to exert effective resistance without any damage, new cracks can be prevented from occurring in the wall between joints and joints, and shearing force can be sufficiently loaded as a bearing wall during an earthquake. .

[Brief description of drawings]

FIG. 1 is a diagram showing a bar arrangement state of rebars for contraction joints showing an embodiment of the first invention of the present application, FIG. 2 is a transverse sectional view thereof, FIG. 3 is an enlarged vertical sectional view of rebars for contraction joints, FIG. FIG. 4 is a graph showing long-term characteristics of rebar for contraction joint, FIG. 5 is a graph showing characteristics at the time of earthquake, FIG. 6 is a drawing showing another embodiment, and FIG. 7 is a graph showing the second invention of the present application. FIG. 8 is a diagram showing an embodiment of a rebar for contraction joint, FIG. 8 is a bar arrangement diagram thereof, FIG. 9 is a diagram showing a rebar for contraction joint when a crack occurs, FIG. 10 is a stress deformation diagram, and FIG. It is a figure which shows the Example of. 1 ... Seismic wall, 2 ... Shrinkage joint, 3 ... Wall transverse line, 4 ...
Reinforcing bar for contraction joint, 5 ... Viscoelastic layer, 6 ... Quartz sand, 7 ...
Longitudinal streak, 8 ... Lateral streak, 9 ... Anchorage, 10 ... Viscoelastic layer, 11
...... Reinforcement for contraction joint, A …… Behavior of rebar for contraction joint, B
... Behavior of lateral wall muscle, C ... New crack initiation point, D ...
… Yield stress

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masanao Ooka 2-13-12 Miyazaki, Miyazaki-ku, Kawasaki-shi, Kanagawa Tokyu Corporation Miyazakidai Single Dormitory (56) References JP-A-55-23222 (JP, A) ) JP-A-60-7972 (JP, A) JP-A-60-55156 (JP, A) JP-A-59-150851 (JP, A) Actual development Sho-58-134503 (JP, U) Actual public 55- 31129 (JP, Y2)

Claims (2)

[Claims] 1. A plurality of walls which are laid out substantially parallel to each other at appropriate intervals in a direction orthogonal to a contraction joint formed on an earthquake-resistant wall of a reinforced concrete building and cut at both sides of the contraction joint. Horizontal stripes; arranged between these horizontal wall stripes in parallel with them and on both side wall parts of the contraction joint by an appropriate length so as to overlap with the horizontal wall stripes, and on the outer surface of which epoxy resin, tar, etc. A rebar for contraction joints coated with a viscoelastic layer; by contacting the surface of the viscoelastic layer with the aggregate in the concrete, to prevent long-term deformation such as dry shrinkage of the concrete Is
As the aggregate that is in contact with the viscoelastic layer slides, the viscoelastic layer itself also creeps and becomes unrestrained to allow dry shrinkage, while short-term deformation loads such as earthquakes occur. On the other hand, the rebar structure of the shrinkage joint of the earthquake resistant wall is characterized in that the viscoelastic layer and the aggregate are configured to effectively engage with each other without sliding. 2. A plurality of walls which are arranged in parallel to each other at appropriate intervals in a direction orthogonal to a contraction joint formed on an earthquake-resistant wall of a reinforced concrete building and are cut at both sides of the contraction joint. Transverse streaks; arranged on the contraction joints and the side wall parts thereof so as to overlap the transverse wall streaks, and the horizontal stirrup and the anchor streaks are welded in a grid pattern and a viscoelastic layer such as epoxy resin or tar is formed on the surface. A rebar for contraction joint to be covered, and by virtue of the surface of the viscoelastic layer being brought into contact engagement with the aggregate in the concrete, the viscoelastic layer can be protected against long-term deformation such as dry shrinkage of the concrete. As the aggregate in contact with the elastic layer slides, the viscoelastic layer itself also creeps and becomes unrestrained to allow dry shrinkage, while on the other hand, against short-term deformation loads such as earthquakes. Is the above viscoelastic layer Reinforcement structures contraction joints of shear walls, characterized by being configured to exert effective resistance without slide mesh with aggregate.